Respiratory System Vocabulary

Respiratory System Review

General Overview

• The respiratory system is crucial for providing oxygen to all body cells.
• It involves external respiration (breathing in and out) and internal respiration (gas exchange at the cellular level).
• The system's primary function is to convert carbon dioxide (CO2) into oxygen and distribute it throughout the body.

Upper Respiratory Tract

• Consists of the nose, pharynx, larynx, and trachea.
• Nose: The entry point for air into the respiratory system.
• Pharynx: Passage for both air and food.
• Larynx: Contains the voice box and vocal cords, responsible for sound production.
  • Vocal cords vibrate as air passes over them during exhalation, producing sound.
  • The size of the vocal cords determines the depth of the voice; larger cords result in a deeper voice.
• Trachea: Also known as the windpipe. It leads down towards the lungs, where an endotracheal tube may be placed during intubation to maintain a patient's airway.
  • A tracheostomy involves creating an opening in the trachea to provide an airway for compromised individuals.
• Sinuses Air-filled spaces in the skull that connect to the nasal cavity, helping to regulate temperature and humidity of inhaled air as well as lightening the weight of the skull. Common sinus issues: sinusitis.
• Nasal Septum: Separates the nasal cavity into two nostrils. A deviated septum refers to when the septum is displaced to one side.
• Epiglottis:
  • A flap that prevents food from entering the lower respiratory tract during swallowing.
  • It opens and closes to direct food and fluids into the esophagus rather than the trachea.

Lower Respiratory Tract

• Includes the lungs, bronchi, and bronchial tree.
• Lungs:
  • The right lung has three lobes, while the left lung has two lobes.
  • The right bronchus is shorter and wider than the left, making the right lung more susceptible to aspiration.
• Bronchi and Bronchial Tree:
  • The trachea branches into the right and left bronchi, which further divide into smaller bronchioles.
  • These bronchioles form the bronchial tree, which distributes air throughout the lungs.
• Alveoli:
  • Small, microscopic sacs where gas exchange occurs.
  • Oxygen and carbon dioxide are exchanged between the alveoli and the bloodstream.

Gas Exchange

• During inhalation, oxygen is drawn into the lungs, while during exhalation, carbon dioxide is expelled.
• Improper gas exchange can lead to complications due to excessive CO2 retention.
• Alveoli play a vital part in gas exchage.

Arterial Blood Gases (ABGs)

• ABGs measure the effectiveness of gas exchange in the lungs.
• They provide information about oxygen levels, carbon dioxide levels, and the pH balance in the blood.
• Key components include:
  • Oxygen (O2):Indicates the amount of oxygen in the blood.
  • Carbon Dioxide (CO2): Reflects the amount of carbon dioxide in the blood.
  • pH: Measures the acidity or alkalinity of the blood.
  • Bicarbonate (HCO3): Relates to kidney function and helps regulate pH.
• Carbon dioxide acts as a chemical stimulant for respiration. High CO2 levels trigger an increase in respiratory rate to expel excess CO2, and visa versa.
• Increased CO2 leads to decreased pH (more acidic), while decreased CO2 leads to increased pH (more alkaline).
• The body compensates for imbalances in CO2 levels by adjusting the respiratory rate to maintain proper pH balance.

Respiratory Assessment

• When completing a head-to-toe assessment, certain things about the patient should be noted.
• Important aspects of a respiratory assessment include:
  • Observation: Color (cyanosis), respiratory rate, depth, and symmetry of chest movement.
  • Auscultation: Listening to lung sounds for abnormalities such as wheezes or crackles (rales).
  • Patient History: Smoking habits (amount and duration), allergies, medical history, and family history of respiratory conditions.
  • Level of Consciousness: Changes in mental status, such as agitation, could indicate low oxygen levels, especially in patients with dementia.
• Lung Sounds:
  • Crackles: Indicate fluid in the lungs, often associated with conditions such as pneumonia or heart failure.
  • Wheezes: Indicate airway narrowing or obstruction.
  • Can be inspiratory or expiratory
• It is important to utilize resources such as YouTube videos to familiarize oneself with different lung sounds.

Diagnostic Tests

• Chest X-ray:
  • Used to assess the size, shape, and position of the lungs.
  • Can confirm conditions such as pneumothorax, pneumonia, and pleural effusion.
  • Normal chest X-rays show clear lung fields, while abnormalities may appear as white patches or "white out."
• CT Scan:
  • Provides a more detailed, in-depth view of the lungs compared to X-rays.
  • Involves taking cross-sectional images of the lungs from different angles.
  • It's important to assess patients for claustrophobia or anxiety prior to the scan because the patient is required to lay still during the procedure.
• Pulmonary Angiography:
  • Examines the blood flow in the lungs, particularly to identify pulmonary embolisms (PE).
• Ventilation/Perfusion (VQ) Scan:
  • Assesses ventilation (airflow) versus perfusion (blood flow) in the lungs.
  • Used to detect areas of mismatched ventilation and perfusion, indicating possible PE.
  • During the scan, patients inhale a gas, and its movement through the lungs is monitored to identify any areas of decreased perfusion.
• Pulmonary Function Test (PFT):
  • Measures lung volumes and capacities to assess overall lung function.
  • Determines how much air a patient can inhale and exhale.
  • Carbon monoxide is used instead of oxygen during the test.
  • Used to track the progression of chronic lung diseases like COPD.
• Bronchoscopy:
  • Involves inserting a scope into the airways to visualize the lungs.
  • Used for diagnostic purposes, such as identifying abnormalities or collecting samples for biopsy.
  • Preoperative care:
    • Informed consent.
    • NPO (nothing by mouth) for at least eight hours prior to the procedure due to anesthesia.
  • Postoperative care:
    • Monitoring vital signs and respiratory status.
    • Ensuring the gag reflex returns before allowing oral intake.
    • Observing for signs of hemorrhage, laryngeal edema, or spasms.
• Sputum Sample:
  • Involves collecting a sample of sputum to analyze its characteristics.
  • Characteristics such as color, odor, and consistency can provide valuable diagnostic information.
• Lung Biopsy:
  • Involves taking a tissue sample from the lungs for analysis.
  • Used to diagnose conditions such as lung cancer or other lung diseases.
  • Can be performed via open or transbronchial approach.
  • Preoperative care: Informed consent, NPO status.
  • Postoperative care: Monitoring for signs of hemorrhage or bleeding.
• Thoracentesis:
  • Involves removing fluid from the pleural space surrounding the lungs.
  • Used to relieve pressure on the lungs and improve breathing.
  • Fluid is drained slowly to avoid complications such as lung collapse.
  • Usually no more than 1300 mL is removed.
  • Complications can include low BP.
  • Postoperative care:
    • Monitoring vital signs, respiratory status, and airway.
    • Placing the patient on the unaffected side.
• Arterial Blood Gas Sampling (ABG):
  • Requires arterial puncture, typically at the wrist or groin.
  • Monitoring is essential to prevent excessive bleeding because arteries have higher pressure than veins.
• Pulse Oximetry:
  • Measures oxygen saturation in the blood continuously.
  • Although continuous monitoring is common in critical care units, there may be specific situations where oxygen of 88% is normal.